Introduction & History

Named for the USDA's Division of Western Exploration and Testing, the Dweet tangor represents California's contribution to the mandarin-orange hybrid category. This deliberate cross, produced at the Citrus Research Center in Riverside, combined the Mediterranean mandarin's easy peeling with sweet orange juice quality. The result is a late-maturing tangor that extends the California citrus season into spring — a period when most mandarins and navels have finished. The Dweet's juice quality is considered among the finest of any tangor, with a balanced sweetness and aromatic depth that makes it outstanding for both fresh eating and premium juice.

History & Origin

Developed at the USDA Citrus Research Center in Riverside, California, from a mandarin × sweet orange cross. The 'Dweet' name comes from the Division of Western Exploration and Testing, the USDA unit responsible for the program. Released for limited commercial evaluation, the variety found its niche as a late-season home garden tangor in California's inland valleys. It has not achieved major commercial planting but is maintained by specialty citrus growers and enthusiasts.

Botanical Description

A medium-sized, moderately vigorous evergreen tree reaching 4–5 m with a rounded, moderately dense canopy. Leaves are medium, elliptic, dark green. Flowers are fragrant and produced in spring. Fruit is medium (6–7 cm), round to slightly oblate, with orange rind of moderate thickness that peels reasonably easily. Flesh is orange, very juicy, sweet, and flavourful with tangor richness. Seeds are moderate (4–8). The late spring maturity (March–May in California) is the variety's distinguishing commercial feature.

Planting & Cultivation

Plant in full sun in well-drained soil with pH 6.0–7.0. Space trees 4–5 m apart. The late maturity means fruit hangs through late winter and spring — select a site with good air drainage and frost protection for the developing fruit. Plant in spring from certified nursery stock.

Cultivation

Manage as a standard mandarin-type citrus. Apply balanced fertiliser 3–4 times per year. The late-maturing fruit requires sustained nutrition through winter and into spring. Potassium application during autumn and winter supports fruit quality during the holding period. Cross-pollination from nearby citrus improves fruit set.

Climate & Cold Protection

Suited to warm Mediterranean and subtropical climates (USDA zones 9b–11). Cold tolerance approximately -2°C. The late-hanging fruit must survive the winter on the tree, making site selection important in frost-prone areas. California's inland valleys provide ideal conditions.

Seasonal Care

Spring: Bloom and late fruit harvest overlap; fertilise; irrigation. Summer: New fruit developing; consistent watering. Autumn: Fruit from spring bloom maturing slowly; reduce nitrogen. Winter: Fruit holding on tree; protect from frost; maintain nutrition. Late winter/spring: Main harvest March–May.

Cold Protection

Standard citrus protection, with special attention to the winter-hanging fruit. Frost blankets during cold events. The fruit itself freezes at approximately -1.5°C.

Seasonal Care Calendar

Propagation

Budded onto Carrizo citrange or C-35 citrange rootstock. Available from specialty California citrus nurseries. Seeds not true-to-type.

Diseases & Pests

Standard California citrus pest profile. The late-hanging fruit is exposed to more pest and disease pressure than early-maturing varieties. Brown rot during winter rains. Scale insects. Monitor for HLB/psyllid.

Harvesting & Culinary Uses

Fruit matures March through May — one of the latest-maturing citrus in California. Harvest when rind is orange and fruit segments easily. Brix 11–13 with good acid balance. The late timing means fresh tangors when other fresh citrus has ended.

Culinary Uses

Dweet's excellent juice quality makes it a premium eating and juicing tangor. Fresh segments in spring salads. The juice makes outstanding cocktails and sorbets. The balanced flavour works well in cooking — use in pan sauces for spring lamb or fish.

Rootstock Guide

Carrizo citrange (California standard). C-35 for slightly smaller trees. Flying Dragon for containers. Trifoliata for cold tolerance in marginal areas.

Container & Companion Growing

Container Growing

Works well in containers (50–60 cm) on dwarfing rootstock. The late fruit provides ornamental interest through winter and into spring when most other citrus has been harvested. Position in full sun.

Companion Planting

Combine with early and mid-season citrus for year-round fruit. The moderate size allows integration into mixed orchards. Plant pollinisers nearby for best fruit quality.

Common Mistakes to Avoid

Not protecting the late-hanging fruit from winter frost. Not providing cross-pollination. Harvesting too early before spring sugar development peaks.

Frequently Asked Questions